The Importance of a Diamond's Cut
Of the 4 C's used to evaluate a diamond - cut, clarity, color,
carat-weight - perhaps the least understood by the general
public is cut. After all, even someone looking for the first
time at a diamond can often see flaws (which affect clarity),
the color, and the relative size of a stone. But, how do you go
about evaluating a diamond's cut?
It's actually not a difficult concept to grasp, once you learn
that cut determines a gem's brilliance (how effectively it
reflects light back toward the viewer's eyes). This is the true
artistry of a diamond cutter's work. The biggest flawless
diamond with the most amazing color can be ruined by a poor cut
that dulls its appearance to the naked eye.
There are, as you probably already know, many popular diamond
cuts. They include: round, oval, marquise, pear, heart, emerald,
princess, and radiant. While some cuts (round and radiant) are
specifically intended to enhance brilliance, a properly cut
diamond of any shape should appear sparkly - not dull - in
There is a lot going on when a diamond cutter does his work, but
for a basic understanding, let's concentrate on the three
primary aspects: depth, symmetry, and polish. Remember that the
main goal when shaping a diamond is to maximize brilliance in
the final version.
Depth refers to how tall a diamond is from top (called the
'table') to bottom (called the 'culet'). The depth partially
determines how the expert cutter will angle the many facets
(flat surfaces) as he shapes the stone. Ideally, those facet
angles will divert incoming light in such a way that it gets
routed down, across, and back up through the diamond. Properly
done, the result is brilliance. Poorly done, the light leaks
through the bottom and/or the sides of the diamond.
Symmetry refers to how well the facets (flat surfaces) are
aligned. With perfect symmetry, a diamond looks 'whole.' It
pleases the eye from any viewing angle. Beyond these overall
aesthetic qualities, symmetry plays a big role in brilliance.
Misalignment or disproportional cuts will wreak havoc on how
light travels through the diamond. Just as with poor depth, poor
symmetry will cause a diamond to appear dull.
Polish refers to the smoothness of the surface of every facet
that is cut into a raw diamond. This part of the diamond cutting
process requires the utmost care and attention to minute detail.
With modern technology, polish does not vary nearly as much now
as it did in years past. Excellent polish greatly enhances a
diamond's brilliance because it creates less diffusion as light
enters and exits the diamond. Even a diamond with slight depth
or symmetry problems will appear brilliant if the polish is of
the highest grade.
To be sure, a lot more is involved than what's covered here.
However, for the average diamond shopper, all you need to know
is whether the diamond shines with brilliance or appears dull.
Specific cut grading details are issued on most diamonds you'll
find being sold in stores or from brokers, if you want the
in-depth evaluation for investment purposes. But, for most of
us, how the diamond looks in terms of brilliance is the way we
evaluate it when deciding to shell out our hard-earned money.
Now you know why that diamond sparkles (or doesn't) - it's all
in the cut!